The present invention relates to a quantitative discharge apparatus and a method of discharging powder material wherein the discharge amount of powder material stored in a tubular body can be easily controlled and powder material can be quantitatively and stably discharged.
The inventors of the present invention have already proposed a device for discharging a minute amount of powder having an elastic membrane with a penetrating port in JP-A-8-161553 as a quantitative discharge apparatus for discharging powder material quantitatively.
FIG. 39 diagrammatically shows a construction of a powder material spray apparatus applying such a device for discharging a minute amount of powder.
The powder material spray apparatus 211 has the device for discharging a minute amount of powder 201 and a pneumatic transport pipe T.
The discharge device 201 has a powder material storage hopper 202 for storing powder material and an elastic membrane Etc provided at a material discharge port 202a of the powder material storage hopper 202 so as to form a bottom of the powder material storage hopper 202.
A cover 202c is attached detachably and airtightly at the material feed port 202b of the powder material storage hopper 202.
The powder material spray apparatus 211 is constructed such that the material discharge port 202a of the powder material storage hopper 202 of the discharge device 201 is connected to the midstream of the pneumatic transport pipe T via the elastic membrane Etc.
The elastic membrane Etc has a penetrating aperture hc at the center thereof as shown in FIG. 40.
One end Ta of the pneumatic transport pipe T is connected to a positive pulsating vibration air generation means 221 so that when the generation means 221 is driven, produced positive pulsating vibration air is supplied in the pneumatic transport pipe T from the end Ta.
Next, operations of the device for discharging a minute amount of powder 201 and the powder material spray apparatus 211 will be explained.
For spraying a fixed amount of powder material from the other end Tb of the pneumatic transport pipe T by means of the powder material spray apparatus 211, at first powder material is stored in the powder material storage hopper 202. Then the cover 202c is airtightly attached to the material feed port 202b of the storage hopper 202.
Driving the positive pulsating vibration air generation means 221, a positive pulsating vibration air is supplied in the pneumatic transport pipe T.
As a positive pulsating vibration air, a pulsating vibration air of which amplitude peak is higher than atmospheric pressure and of which amplitude valley is substantially at atmospheric pressure as shown in FIG. 41a or a pulsating vibration air of which amplitude peak and amplitude valley are higher than atmospheric pressure as shown in FIG. 41b may be used.
When a positive pulsating vibration air is supplied in the pneumatic transport pipe T of the device for discharging a minute amount of powder 201, the pressure in the pneumatic transport pipe T is increased at the peak amplitude of the pulsating vibration air and the elastic membrane Etc is elastically deformed to be upwardly curved being a specific point as the center of the node of vibration.
At this time the penetrating aperture hc is shaped like a letter V in such a manner that the top is opened in section.
A part of powder material stored in the powder material storage hopper 202 drops in the V-shaped penetrating aperture hc (see FIG. 42a).
Next, the positive pulsating vibration air supplied in the pneumatic transport pipe T becomes its valley, the pressure in the pneumatic pipe T is gradually reduced and the elastic membrane Etc returns its original position from the upwardly curved shape. The penetrating aperture hc is returned to its original shape from the V-shape with the top open. In this case the powder material dropped in the penetrating aperture hc when its top has been opened is caught in the aperture hc (see FIG. 42b).
When the positive pulsating vibration air becomes its valley and the pressure in the pneumatic transport pipe T is reduced, the elastic membrane Etc is elastically deformed to be curved downwardly being a specific point as the center of vibration node. The penetrating aperture hc is shaped like a reverse V of which bottom is opened. The powder material caught in the aperture hc drops in the pneumatic transport pipe T when the aperture hc is formed like a reverse V (see FIG. 42c).
The powder material dropped in the pneumatic transport pipe T is mixed with and dispersed in the positive pulsating vibration air supplied therein.
Then, the powder material dropped in the pneumatic transport pipe T is pneumatically transported to the end Tb of the pipe T to be sprayed therefrom together with the positive pulsating vibration air.
The vibration of the elastic membrane Etc, according to the powder material spray apparatus 211, is only defined by the positive pulsating vibration air supplied in the pneumatic transport pipe T. The amount of powder material supplied in the pipe T via the penetrating aperture hc is defined by the vibration of the elastic membrane Etc. Therefore, as long as the positive pulsating vibration air supplied in the pipe T is constant, a fixed amount of powder material is discharge in the pipe T.
Therefore, almost all of the powder material supplied via the penetrating aperture hc of the elastic membrane Etc into the pneumatic transport pipe T can be sprayed from the other end Tb thereof.
In the powder material spray apparatus 211, spray from the other end Tb of the pneumatic transport pipe T can be executed as long as the positive pulsating vibration air is supplied from the end Ta of the pipe T.
On the other hand, in order to increase the discharge amount of powder material in the pneumatic transport pipe T of the device for discharging a minute amount of powder 201, the size of the penetrating aperture hc of the elastic membrane may be enlarged or the plural numbers of penetrating apertures hc may be provided.
However, if the size of the penetrating aperture hc of the elastic membrane Etc is enlarged more than a fixed size, there is a problem that the aperture hc is opened larger than an expected area because of the resilience of the elastic membrane Etc so that the discharge amount of powder material of the device for discharging a minute amount of powder 201 is difficult to be controlled at a desirable amount.
Further, there arise problems such that the tensile strength of the elastic membrane Etc lacks uniformity because of the large penetrating aperture hc formed on the elastic membrane Etc and when a positive pulsating vibration air is supplied to the membrane Etc, the membrane Etc doesn""t vibrate in response to the positive pulsating vibration air or the quantitativeness of the discharge amount of powder material from the device for discharging a minute amount of powder 201 is damaged.
Therefore, the size of the penetrating aperture hc on the elastic membrane Etc can""t be completely defined depending on the component of discharged powder material, the tensile strength of the elastic membrane Etc being stretched and the size and the thickness of the elastic membrane Etc. However, the size of the penetrating aperture hc of the membrane Etc has its upper limit.
On the other hand, the inventors of the present invention have found that even if an elastic membrane having plural penetrating apertures hr . . . like the one EtcA as shown in FIG. 43 is attached to the device for discharging a minute amount of powder 201 and the device 201 is driven, the discharge amount of powder material in the pneumatic transport pipe T isn""t increased at a rate of the number of the plural apertures hr . . . .
According to the elastic membrane EtcA having plural penetrating apertures hr at random as shown in FIG. 43, some parts of the elastic membrane EtcA have different tensile strengths so that the membrane Etca vibrates unevenly and its reproducibility and response to the positive pulsating vibration air become worse when a positive pulsating vibration air is supplied in the pneumatic transport pipe T. As a result, the inventors of the present invention have found that there has been a problem such that the quantitativeness of the powder material discharged in the pipe T is deteriorated.
Further according to the device for discharging a minute amount of powder material 201, the inventors have found that it is difficult to attach the elastic membrane Etc and EtcA to the discharge device 201 while being evenly stretched. Moreover, if the elastic membranes Etc and EtcA are successfully attached on the discharge device 201 while being uniformly expanded, the membranes Etc and EtcA get slack in time during a discharge operation of powder material in which the positive pulsating vibration air is supplied to vibrate the membranes Etc and EtcA and powder material is discharged from the penetrating aperture hs or the plural apertures hr . . . .
The present invention which has been proposed to solve the above-mentioned problems relates to a quantitative discharge apparatus having an elastic membrane with a penetrating aperture and a discharge method of powder material by means of an elastic membrane with a penetrating aperture. The object of the present invention is to provide a quantitative discharge apparatus and a discharge method of powder material wherein the discharge amount of powder material quantitatively varies while keeping a substantially positive relation depending on the number of penetrating apertures formed on an elastic membrane so that the discharge amount of powder from the quantitative discharge apparatus can be controlled and wherein the quantitativeness of discharge amount of powder material is superior.
Further, the object of the present invention is to provide a quantitative discharge apparatus and a discharge method wherein even if plural penetrating apertures are provided on the elastic membrane, the elastic membrane can be uniformly and evenly expanded at a fixed tensile strength in an easy and simple operation and wherein the elastic membrane doesn""t get slack while the quantitative discharge apparatus is operated.
The quantitative discharge apparatus for powder material of the present invention comprises a tubular body for storing powder material and an elastic membrane having plural penetrating apertures, the membrane constituting a bottom of the tubular body. The elastic membrane is vibrated by applying a positive pulsating vibration air thereto in a manner that the vibration node appears at the periphery of the elastic membrane, and thereby powder material stored in the tubular body is discharged from the plural penetrating apertures of the elastic membrane.
In this specification the term xe2x80x9cpositive pressurexe2x80x9d means a pressure which is higher than atmospheric pressure out of the quantitative discharge apparatus.
The term xe2x80x9cpulsating vibration airxe2x80x9d in this specification means an air flow which presents like a wave repeating a high pressure part and a lower pressure part alternately.
The term xe2x80x9cpositive pulsating vibration airxe2x80x9d in this specification includes a positive pulsating vibration air in which its amplitude peak and valley are both positive and a positive pulsating vibration air in which its amplitude peak is positive pressure and its amplitude valley is atmospheric pressure.
The positive pulsating vibration air is supplied into the elastic membrane to make the membrane vibrate being its periphery as a node of vibration.
In this quantitative discharge apparatus, plural penetrating apertures are formed on the elastic membrane so that the discharge amount of powder material from the quantitative discharge apparatus can be increased at the ratio of the increased number of the apertures comparing with the elastic membrane with one penetrating aperture even if the conditions of the positive pulsating vibration air supplied into the elastic membrane aren""t changed.
According to the quantitative discharge apparatus of the present invention, the plural penetrating apertures of the elastic membrane are formed in a point symmetrical manner with respect to a specific point on the elastic membrane.
The phrase xe2x80x9cthe plural penetrating apertures of the elastic membrane are formed in a point symmetrical manner with respect to a specific point on the elastic membranexe2x80x9d doesn""t mean that the number of the penetrating apertures formed on the elastic membrane is limited to two. Namely, the phrase includes the case when more than two penetrating apertures exist.
It means that two penetrating apertures are paired among more than two apertures against a specific point when more than two penetrating apertures are observed against the point and two apertures are formed in a point symmetrical manner with respect to the specific point per each paired two penetrating apertures.
According to this quantitative discharge apparatus, the elastic membrane with plural penetrating apertures formed in a point symmetrical manner with respect to a specific point is used. When a positive pulsating vibration air is supplied into the elastic membrane to be vibrated with its periphery being a node of vibration, the discharge amount of powder material from the quantitative discharge apparatus can be increased comparing with the case when the elastic membrane having plural penetrating apertures with the same number and the same shape at random under the same condition of the positive pulsating vibration air.
According to the quantitative discharge apparatus of the present invention, the plural penetrating apertures of the elastic membrane are formed in an axial symmetrical manner with respect to a line passing on a specific point on the elastic membrane.
The phrase xe2x80x9cthe plural penetrating apertures of the elastic membrane are formed in an axial symmetrical manner with respect to a line passing on a specific point on the elastic membranexe2x80x9d doesn""t mean that the number of the penetrating aperture formed on the elastic membrane is limited to two. Namely, the phrase includes the case when more than two penetrating apertures exist.
It means that when more than two penetrating apertures are observed against the line passing on the specific point, two apertures among them are formed in an axial symmetrical manner with respect to the line passing through the line.
There is one line passing on the specific point in case of two penetrating apertures and there are xe2x80x9cnxe2x80x9d lines in case of xe2x80x9cnxe2x80x9d (nxe2x89xa73) numbers of penetrating apertures.
According to this quantitative discharge apparatus, the elastic membrane with plural penetrating apertures formed in an axial symmetrical manner with respect to the line passing on the specific point is used. When a positive pulsating vibration air is supplied to vibrate the elastic membrane with its periphery being a node of vibration, the discharge amount of powder material from the quantitative discharge apparatus can be increased comparing with the case when the elastic membrane having plural penetrating apertures with the same number and the same shape at random under the same condition of the positive pulsating vibration air.
According to the quantitative discharge apparatus of the present invention, the plural penetrating apertures of the elastic membrane are formed on a circumference of a virtual circle, the center of which is the specific point on the elastic membrane.
The term xe2x80x9cformed on a circumference of a virtual circlexe2x80x9d may be on the same circumference of a virtual circle around a specific point or may be on the circumferences of different cocentric circles around different points.
According to this quantitative discharge apparatus, a virtual circle is drawn around a specific point on the elastic membrane and plural penetrating apertures are formed on its circumference. When each one of the plural penetrating apertures has the same size and shape, it shows the same behavior (the same deformation (expansion and contraction)) in case that a positive pulsating vibration air is supplied into the elastic membrane to be vibrated with its periphery being a vibration node.
As a result, if the positive pulsating vibration air supplied into the elastic membrane is constant and the penetrating apertures with the same size and shape are formed on the elastic membrane, the discharge amount of powder material from the quantitative discharge apparatus can be increased in a positive correlation to the number of the penetrating apertures on the elastic membrane.
According to the quantitative discharge apparatus of the present invention, the plural penetrating apertures of the elastic membrane are formed at even intervals on the circumference of a specific virtual circle.
If a virtual circle is drawn around a specific point on the elastic membrane and penetrating apertures with the same size and shape are partialized on an area, the elastic membrane isn""t stretched uniformly and evenly because of the partialized apertures. Further, when the elastic membrane is vibrated by the positive pulsating vibration air, it shows irregular vibration.
Contrarily, in this quantitative discharge apparatus, a virtual circle is drawn around a specific point on the elastic membrane and plural penetrating apertures are formed at even intervals on the circumference of the virtual circle. If each one of plural penetrating apertures has the same size and shape, the elastic membrane can execute vibration with high reproducibility with its center being a vibration antinode and its periphery being a vibration node when the positive pulsating vibration air is supplied on the elastic membrane.
According to this quantitative discharge apparatus, comparing with the quantitative discharge apparatus using the elastic membrane on which plural penetrating apertures are partialized on an area, the discharge amount of powder material is quantitatively changed keeping a positive relation to the number of the penetrating apertures on the elastic membrane.
Namely, according to this quantitative discharge apparatus, the number of penetrating apertures are increased in such a manner that a virtual circle is drawn around a specific point on the elastic membrane and plural numbers of the apertures are formed at even intervals on the circumference of the virtual circle, thereby the discharge amount of powder material is quantitatively changed keeping a positive relation to the number of the penetrating apertures on the elastic membrane.
According to the quantitative discharge apparatus of the present invention, each one of the plural penetrating apertures of the elastic membrane is formed as a cut aperture.
If each penetrating aperture on the elastic membrane is formed as a cut aperture (slit) and the elastic membrane isn""t curved up and down, the cut aperture (slit) is closed so that the powder material on the elastic membrane isn""t discharged therethrough.
When the elastic membrane is curved upward by a positive pulsating vibration air, the cut aperture (slit) becomes V-shaped with its top open seen from its section except that the cut apertures (slit) are formed radial into periphery from a specific point being the center of the virtual circle when the virtual circle is drawn on the elastic membrane. The powder material on the elastic membrane is dropped in the V-shaped cut aperture (slit) with its top open.
When the elastic membrane returns to its original position (wherein it isn""t curved up and down), the cut aperture (slit) also returns to its original closed position. At this time, the powder material dropped in the aperture (slit) when its top is opened like a letter V is kept being caught therein.
Further, when the elastic membrane is curved down by a pulsating vibration air, the cut aperture (slit) becomes a reverse V shape with its bottom open except that the apertures (slit) are formed radial into periphery from a specific point being the center of the virtual circle when the virtual circle is drawn on the elastic membrane. The powder material which has been dropped in the V-shaped aperture (slit) with its top open and been caught therein when the membrane is its original position (wherein it isn""t curved up and down) is discharged under the elastic membrane.
The above-mentioned operations of the cut aperture (slit) formed on the elastic membrane are reproduced as long as the elastic membrane repeats the same vibration.
The up-and-down vibration of the elastic membrane only depends on the positive pulsating vibration air supplied into the elastic membrane. Namely, as long as the positive pulsating vibration air supplied onto the elastic membrane is constant, the membrane repeats the same vibration up and down, thereby reproducing the operation of the cut aperture (slit) as mentioned above.
Accordingly, as long as each one of the plural penetrating apertures formed on the elastic membrane of the quantitative discharge apparatus is a cut aperture (slit) and the positive pulsating vibration air supplied to the elastic membrane is constant, the discharge amount of powder material from the apertures (slit) formed on the membrane is designed to be constant, thereby achieving high quantitativeness of the discharge amount of powder material.
When each one of the plural penetrating apertures formed on the elastic membrane is a cut aperture (slit), the cutting direction of the apertures may be a tangential direction on the circumference of a virtual circle, may have an angle against the tangent on virtual circle or may be radial direction from a specific point used as the center of the virtual circle.
If each one of the plural penetrating apertures formed on the elastic membrane is arranged on the same circumference of a virtual circle, is a cut aperture (slit) and has the same cut length, when the positive pulsating vibration air is supplied on the elastic membrane to be vibrated and the powder material stored and accumulated on the elastic membrane is discharged from the cut apertures, the discharge amount of powder material from the cut apertures generally has the following relation: the discharge amount from the cut apertures (slit) which are formed on a tangent of a virtual circle around a specific point on the elastic membrane greater than the discharge amount from the cut apertures (slit) which are formed on a line with a specific angle against the tangent of a virtual circle around a specific point on the elastic membrane greater than the discharge amount from the cut apertures (slit) which are formed in a radial direction from a specific point used as a center of a virtual circle.
Therefore, the discharge amount of powder material in the quantitative discharge apparatus can be controlled by means of the cut apertures formed on the elastic membrane such that the number, the length and the arranging direction of the cut apertures (slit) are varied without changing the supply conditions of the positive pulsating vibration air supplied in the quantitative discharge apparatus.
According to the quantitative discharge apparatus of the present invention, a cutting direction of the cut aperture on the elastic membrane is a tangential direction of the circumference of a specific virtual circle.
When a positive pulsating vibration air is supplied onto the elastic membrane to be vibrated being its periphery as a vibration node and being its center as a vibration antinode, if the cutting direction of the cut apertures (slit) is a tangential direction of the circumference on which plural apertures are formed, the elastic membrane is curved upward by the positive pulsating vibration air so that the aperture (slit) is V-shaped with its top open and it is curved downward by the air so that the aperture (slit) becomes reverse V-shape with its bottom open.
According to this quantitative discharge apparatus, the cutting direction of the apertures (slit) is a tangential direction of the circumference on which plural apertures are formed and the elastic membrane repeats the cycle at high reproducibility wherein each plural aperture is opened like a letter V and is closed like a reverse letter V when the elastic membrane is vibrated by the positive pulsating vibration air supplied thereto. Therefore, a large amount of powder material can be quantitatively discharged through the cut apertures (slit) comparing with the quantitative discharge apparatus using the elastic membrane on which the apertures with the same shape, the same size and the same number are formed in radial direction from the virtual circle to its periphery.
According to the quantitative discharge apparatus of the present invention, a penetrating aperture is further provided on a specific point on the elastic membrane.
The penetrating aperture may be an aperture which is always opened or a cut aperture (slit). Considering the quantitativeness of powder material discharged from the quantitative discharge apparatus, it may be a cut aperture (slit).
In such a discharge apparatus, the penetrating aperture is provided at a specific point which is a center of a virtual circle on the elastic membrane, thereby further enabling to increase the discharge amount of powder material while keeping a positive relation.
According to the quantitative discharge apparatus of the present invention, the discharge amount of powder material in the quantitative discharge apparatus is adjustable at a desired value depending on the number of the plural penetrating apertures formed on the elastic membrane. A predetermined number of penetrating apertures are at first formed on a tangent of the circumference of a specific virtual circle on the elastic membrane, the tangent including the contact point with the circumference. Then a predetermined number of penetrating apertures are next formed on a line with a specific angle across the tangent of the circumference of a specific virtual circle on the elastic membrane, the line including the contact point with the circumference.
Here the term xe2x80x9ca predetermined numberxe2x80x9d of xe2x80x9ca predetermined number of penetrating aperturesxe2x80x9d formed on a tangent of the virtual circle means more than one. Further, xe2x80x9ca predetermined numberxe2x80x9d of xe2x80x9ca predetermined number of penetrating aperturesxe2x80x9d provided on a line with a specific angle across the tangent of the virtual circle means more than one. The virtual circle on which a predetermined number of penetrating apertures are formed on a line with a specific angle across the tangent of the circle may be the same as a virtual circle on which a predetermined number of penetrating apertures are formed on its tangent or may be on the circumference of a different cocentric circle.
If each one of the plural penetrating apertures formed on the elastic membrane is arranged on the same circumference of a virtual circle, is a cut aperture (slit) and has the same cut length, when the positive pulsating vibration air is supplied on the elastic membrane to be vibrated and the powder material stored and accumulated on the elastic membrane is discharged from the cut apertures, the discharge amount of powder material from the cut apertures generally has the following relation: the discharge amount from the cut apertures (slit) which are formed on a tangent of a virtual circle around a specific point on the elastic membrane greater than the discharge amount from the cut apertures (slit) which are formed on a line with a specific angle across the tangent of the virtual circle around a specific point on the elastic membrane.
According to this quantitative discharge apparatus, for controlling the discharge amount of powder material from the quantitative discharge apparatus, when the discharge amount of powder material from the apparatus is remarkably small comparing with the objective amount, the discharge amount of powder material from the apparatus is subject to be approached to the objective discharge amount with a small number of penetrating apertures (cut aperture (slit)) being formed on the tangent of a virtual circle drawn around a specific point. Thereafter, penetrating apertures (cut aperture (slit)) are formed on the circumference of the virtual circle drawn around a specific point so as to have an angle against the tangent of the circle so that the discharge amount of powder material is controlled to be an objective amount. As a result, the amount of powder material discharged from the quantitative discharge apparatus can be accurately controlled to be an objective amount.
According to the quantitative discharge apparatus of the present invention, a predetermined number of penetrating apertures on the elastic membrane are formed on the circumference of the virtual circle around the specific point on the elastic membrane in a radial direction from the specific point of the virtual circle.
The term xe2x80x9ca predetermined numberxe2x80x9d of xe2x80x9ca predetermined number of penetrating aperturesxe2x80x9d formed on the circumference of the virtual circle in radial direction from the center of the virtual circle means more than one. The virtual circle on which a predetermined number of penetrating apertures are formed so as to have an angle against the tangent of the circle means that the virtual circle may be the same as the virtual circle on which a predetermined number of penetrating apertures are formed on a tangent of the circle or may be on a different cocentric circle.
If each one of the plural penetrating apertures formed on the elastic membrane is arranged on the same circumference of a virtual circle, is a cut aperture (slit) and has the same cut length, when the positive pulsating vibration air is supplied on the elastic membrane to be vibrated and the powder material stored and accumulated on the elastic membrane is discharged from the cut penetration apertures, the discharge amount of powder material from the cut apertures becomes a minimum when the cutting direction of the cut aperture (slit) is radial from the center of the virtual circle on the elastic membrane.
According to this quantitative discharge apparatus, for controlling the discharge amount of powder material from the quantitative discharge apparatus, when the discharge amount of powder material from the apparatus is remarkably small comparing with the objective amount, the discharge amount of powder material from the apparatus is subject to be approached to the objective discharge amount with a small number of penetrating apertures (cut aperture (slit)) being formed on the tangent of the virtual circle drawn around a specific point. Thereafter, penetrating apertures (cut aperture (slit)) are formed on the circumference of the virtual circle drawn around a specific point so as to have an angle against the tangent of the circle so that the discharge amount of powder material is controlled to be an objective amount. Further, cut apertures (slit) are formed on the circumference of the virtual circle in radial from the center of the virtual circle on the elastic membrane, thereby the discharge amount of powder material is further minutely controlled to the objective amount. As a result, the amount of powder material discharged from the quantitative discharge apparatus can be more accurately controlled to be an objective amount.
According to the quantitative discharge apparatus of the present invention, the specific point on the elastic membrane accords with the center of the outline shape of the elastic membrane.
When the periphery of the elastic membrane is fixed and a positive pulsating vibration air is supplied to such an elastic membrane, the elastic membrane vibrates by the positive pulsating vibration air generally in such a manner that the periphery of the membrane becomes a node of vibration and the center thereof becomes an antinode of vibration.
In this case, when a virtual circle is drawn around the center of the outline shape of the elastic membrane, the elastic membrane executes substantially similar deformation (expansion and contraction) on the virtual circle according to the positive pulsating vibration air.
Therefore, if a virtual circle is drawn around the center of the outline shape of the elastic membrane and plural penetrating apertures with the same size and shape are formed on the virtual circle, each one of plural penetrating apertures provided on the elastic membrane executes the same deformation (expansion and contraction) by the vibration of the elastic membrane, namely by the positive pulsating vibration air, thereby the same amount of powder material can be discharged from each one of the penetrating apertures.
Namely, according to this quantitative discharge apparatus, the center of the dimensional virtual circle drawn on the elastic membrane agrees with the center of the elastic membrane which is the center of the antinode of vibration when the membrane is vibrated by the positive pulsating vibration air and plural penetrating apertures are formed on thus drawn virtual circle, thereby the apertures represent substantially the same behavior.
As the result, when the positive pulsating vibration air supplied to the elastic membrane is constant, the quantitative discharge apparatus can quantitatively vary the discharge amount of powder material while the discharge amount keeps an almost positive relation to the number of the penetrating apertures formed on the membrane.
According to the quantitative discharge apparatus of the present invention, the specific point on the elastic membrane accords with a center of gravity of the elastic membrane.
When a positive pulsating vibration air is supplied to vibrate the elastic membrane with the periphery fixed, the elastic membrane vibrates in such a manner that the center of gravity of the membrane becomes an antinode and the periphery thereof becomes a node of vibration.
In this case, the center of gravity may accords with the center of the outline shape of the elastic membrane or they may be different.
When the elastic membrane with the periphery fixed is vibrated by the positive pulsating vibration air such that the center of gravity of the membrane becomes an antinode and the periphery thereof becomes a node of vibration, if a virtual circle is drawn around the center of gravity of the elastic membrane, the elastic membrane performs substantially the same deformation (expansion and contraction) on the virtual circumference according to the positive pulsating vibration air.
Therefore, if a virtual circle is drawn around the center of gravity of the elastic membrane and plural penetrating apertures with the same size and shape are formed on the virtual circle, each one of plural penetrating apertures provided on the elastic membrane executes the same deformation (expansion and contraction) by the vibration of the elastic membrane, namely by the positive pulsating vibration air, thereby the same amount of powder material can be discharged from each one of the penetrating aperture.
Namely, according to this quantitative discharge apparatus, the center of the virtual circle drawn on the elastic membrane agrees with the center of gravity thereof which is the center of the antinode of vibration when the membrane is vibrated by the positive pulsating vibration air and plural penetrating apertures are formed on thus drawn virtual circle, thereby the apertures represent substantially the same behavior.
As the result, when the positive pulsating vibration air supplied to the elastic membrane is constant, the quantitative discharge apparatus can quantitatively vary the discharge amount of powder material while the discharge amount keeps an almost positive relation to the number of the penetrating apertures formed on the membrane.
According to the quantitative discharge apparatus of the present invention, the specific point on the elastic membrane accords with a center of the node of vibration which appears on the elastic membrane when the positive pulsating vibration air is supplied into the elastic membrane.
In case that the elastic membrane has uneven thickness, its attaching condition and stretching condition aren""t uniform, or there are other causes, the membrane sometimes vibrates in such a manner that the area other than the center of the outline shape of the membrane or the center of gravity of the membrane becomes an antinode of vibration when a positive pulsating vibration air is supplied to the elastic membrane with its periphery fixed.
In this case, after attaching the elastic membrane with one penetrating apertures on the dimensional center or the gravity center of the membrane, how the membrane vibrates is examined by supplying a positive pulsating vibration air on the membrane. Then, a virtual circle is drawn around the antinode of vibration when the elastic membrane is vibrated and plural penetrating apertures are formed on the virtual circle.
When a positive pulsating vibration air is supplied to vibrate the elastic membrane with the periphery fixed, if a virtual circle is drawn around the center of the vibration on the membrane, the elastic membrane executes substantially the same deformation (expansion and contraction) by the positive pulsating vibration air on the virtual circle.
Namely, according to this quantitative discharge apparatus, the virtual circle is drawn around the center of antinode of vibration on the elastic membrane, the antinode being made by the positive pulsating vibration air supplied on the elastic membrane, and plural penetrating apertures are formed on thus drawn virtual circle, thereby the apertures represent substantially the same behavior.
As the result, when the positive pulsating vibration air supplied to the elastic membrane is constant, the quantitative discharge apparatus can quantitatively vary the discharge amount of powder material while the discharge amount keeps an almost positive relation to the number of the penetrating apertures formed on the membrane.
According to the quantitative discharge apparatus of the present invention, the positive pulsating vibration air is supplied from below the elastic membrane.
For supplying the positive pulsating vibration air under the elastic membrane, the lower part of the quantitative discharge apparatus under the elastic membrane is connected to a midstream of a pneumatic transport pipe and the positive pulsating vibration air for pneumatic transportation is supplied from one end of the pipe, therefore, the elastic membrane of the quantitative discharge apparatus connected in a midstream of the pipe is vibrated. Constructing such that, the elastic membrane can be vibrated in synch with the positive pulsating vibration air for pneumatic transportation which runs through the pneumatic transport pipe.
The powder material discharged from the plural penetrating apertures formed on the elastic membrane is pneumatically transported by the positive pulsating vibration air in the pneumatic transport pipe and is sprayed from the other end of the pipe together with the positive pulsating vibration air.
On the other hand, powder material is pneumatically transported by a steady flow air in the pneumatic transport pipe, accumulation or pinhole phenomena of powder material are caused in the pipe and there arises a problem such that the material stays in the pipe. However, in case of supplying a positive pulsating vibration air, the accumulation or pinhole phenomena isn""t caused in the pipe.
Therefore, when a positive pulsating vibration air is supplied in the pneumatic transport pipe, almost all of the powder material discharged from the penetrating apertures on the elastic membrane can be sprayed from the other end of the pipe.
Namely, this quantitative discharge apparatus is constructed in a manner that a positive pulsating vibration air is supplied under the elastic membrane so that a powder material spray apparatus with high quantitativeness which accurately sprays powder material with a desirable concentration at a desired place can be easily composed by utilizing a positive pulsating vibration air supplied for vibrating the elastic membrane as a pneumatic transport means of the powder material discharged from the plural penetrating apertures of the elastic membrane.
According to the quantitative discharge apparatus of the present invention, the positive pulsating vibration air is supplied from above the powder material stored in the tubular body.
When the positive pulsating vibration air is supplied into the powder materials stored in the tubular body from the top thereof, the elastic membrane is formed like a cone area of the tubular body because of the weight of the powder material stored in the tubular body and the positive pressure of the pulsating vibration air, thereby the same construction as hopper can be obtained by the tubular body and the elastic membrane.
Herewith, almost all of the powder material stored in the tubular body can be discharged from the plural penetrating apertures of the elastic membrane.
There has been a problem that the discharge amount of powder material from the material discharge port is varied because of the caked material which has been caused on the cone part of a conventional hopper. However, in this quantitative discharge apparatus, the cone part of the elastic membrane formed by the powder material stored in the tubular body and by the positive pulsating vibration air supplied therein is vibrated by the positive pulsating vibration air, therefore caking of powder material isn""t generated on the elastic membrane.
Namely, the quantitative discharge apparatus is constructed such that the positive pulsating vibration air is supplied from above the powder material stored in the tubular body so that caking of powder material doesn""t occur on the cone like a conventional hopper. Therefore such a quantitative discharge apparatus is superior in quantitativeness of the discharge material from the plural penetrating apertures.
According to the quantitative discharge apparatus of the present invention, the elastic membrane is attached to the lower portion of the tubular body with by means of an elastic membrane installation means. The elastic membrane installation means comprises a pedestal with an opening at its center, a push-up member with an opening at its center, which is disposed in the standing status on the pedestal and a presser member with an opening at its center, the opening being a little larger than the periphery size of the push up member. The pedestal has on its surface an annular V-groove so formed as to surround the opening of the pedestal outside of the periphery of the push-up member and outside of the opening of the pedestal, whereas the presser member has on its surface facing the pedestal an annular V-shape projection portion so formed as to engage into the annular V-groove on the surface of the pedestal. The push-up member is disposed on the surface of the pedestal, on which the elastic membrane is disposed, and further the presser member is so tightly secured as to cover the push-up member together with the elastic membrane to the pedestal, whereby the elastic membrane is expanded from its inner side to its outer side by being pushed up toward the presser member by means of the push-up member, while the periphery part of the elastic membrane is held between the periphery part of the push-up member and the surface forming an opening of the presser member and further expanded to be held between the annular V-groove formed on the surface of the pedestal and the annular V-shape projection portion formed on the surface facing the pedestal, and wherein the presser member is secured to the lower portion of the tubular body.
According to this quantitative discharge apparatus, the elastic membrane with plural penetrating apertures is attached to the lower part of the tubular body by means of the elastic membrane installation means. The elastic membrane is placed on the push-up member placed on the pedestal and the presser member is tightened to the pedestal, thereby the membrane is pushed into the presser member by the push-up member. As a result, the elastic membrane is expanded from its inner side to its outer side when being pushed into the direction of the presser member.
At first, the elastic membrane expanded by the push-up member is gradually inserted between the V-groove formed on the pedestal and the V-shaped projection formed on the surface of the presser member facing the pedestal via the space between the periphery of the push-up member and the surface (inner surface) forming the opening of the presser member.
Furthermore, as the presser member is fastened to the pedestal, the elastic membrane comes to be held between the periphery of the push-up member and the inner surface of opening of the presser member while being pushed up into the presser member by the push-up member. When the elastic membrane is further pushed up into the presser member by the push-up member, the expanded part of the elastic membrane from inside to outside is held between the V-groove of the pedestal and the V-shaped projection on the surface of the presser member 64 facing the pedestal.
As mentioned above, according to this quantitative discharge apparatus, the elastic membrane can be uniformly stretched by a simple operation such that the elastic membrane is placed on the push-up member on the pedestal and the presser member is tightened to the pedestal.
According to the quantitative discharge apparatus of the present invention, an inclined plane is formed on the periphery of the push-up member, the inclined plane having a bottom part broader than its top part when seen in section.
The inclined plane which is enlarged from top to bottom is provided for the periphery of the push-up member of the elastic membrane installation means of the quantitative discharge apparatus. Therefore, the expanded part of the elastic membrane from inside to outside by being pushed up into the presser member is easily moved between the V-groove annularly formed on the pedestal and the V-shaped projection annularly formed on the surface of the presser member facing the pedestal.
When the presser member is fastened to the pedestal, the distance between the inclined plane of the periphery of the push-up member and the inner circumference of opening of the presser member becomes small, and the elastic membrane is tightly held between the inclined plane of the push-up member and the inner circumference of opening of the presser member, preventing the elastic membrane from being slack.
Thus, the elastic membrane doesn""t get slack during usage so that the quantitative discharge apparatus can keep its accurate operation for a long time.
The quantitative discharge apparatus is constructed such that the inclined plane is formed on the periphery of the push-up member when seen sectionally. For attaching the elastic membrane on the elastic membrane installation means, the elastic membrane can be kept evenly and uniformly expanded by a simple operation such that the elastic membrane is placed on the push-up member on the pedestal and the presser member is tightened to the pedestal. Further, the elastic membrane of the quantitative discharge apparatus doesn""t get slack during operation, thereby the quantitative discharge apparatus capable of keeping accurate operation for a long time can be achieved.
Discharge methods for powder material are defined for each above-mentioned quantitative discharge apparatus are defined.
The method of discharging powder material comprising the steps of storing powder material in a tubular body to which an elastic membrane with plural penetrating apertures is attached so that it constitutes a bottom of the tubular body, vibrating the elastic membrane by applying positive pulsating vibration air thereto so as to make the elastic membrane vibrate in a manner that the vibration node appears at its periphery, and thereby discharging the powder material stored in the tubular body from the plural apertures.
According to this discharge method for powder material, the elastic membrane is vibrated by applying the positive pulsating vibration air being its periphery as a node of vibration. Because the vibration of the elastic membrane depends on the positive pulsating vibration air, the elastic membrane repeats a constant vibration depending on the positive pulsating vibration air if a constant positive pulsating vibration air is supplied.
The discharge amount of powder material per time from the plural penetrating apertures on the elastic membrane also depends on vibration of the elastic membrane. If the vibration pattern of the elastic membrane is the same, constant amount of material can be always discharged.
Therefore, applying this discharge method of powder material, when a constant positive pulsating vibration air is used, the discharge amount of powder material per time from the plural penetrating apertures of the elastic membrane can be always constant. Thereby, quantitative discharge of a minute amount of powder material which has been considered to be difficult in a prior art can be accomplished.
In this discharge method of powder material, because plural penetrating apertures are formed on the elastic membrane, the discharge amount of powder material from the quantitative discharge apparatus can be increased in a ratio of the increased number of the penetrating apertures comparing with the elastic membrane having one penetrating aperture unless the conditions of the positive pulsating vibration air are changed.
According to the method of discharging powder material of the present invention, the plural penetrating apertures of the elastic membrane are formed in a point symmetrical manner with respect to a specific point on the elastic membrane.
According to this method of discharging powder material, the elastic membrane with plural penetrating apertures formed in a point symmetrical manner with respect to a specific point is used. When a positive pulsating vibration air is supplied into the elastic membrane to be vibrated with its periphery being a node of vibration, the discharge amount of powder material from the quantitative discharge apparatus can be increased comparing with the case when the elastic membrane having plural penetrating apertures with the same number and the same shape formed at random is used under the same condition of the positive pulsating vibration air.
According to the method of discharging powder material of the present invention, the plural penetrating apertures of the elastic membrane are formed in an axial symmetrical manner with respect to a line passing on a specific point on the elastic membrane.
According to this method of discharging powder material, the elastic membrane with plural penetrating apertures formed in an axial symmetrical manner with respect to the line passing on the specific point is used. When a positive pulsating vibration air is supplied into the elastic membrane to be vibrated with its periphery being a node of vibration, the discharge amount of powder material from the quantitative discharge apparatus can be increased comparing with the case when the elastic membrane having plural penetrating apertures with the same number and the same shape formed at random is used under the same condition of the positive pulsating vibration air.
According to the method of discharging powder material of the present invention, the plural penetrating apertures of the elastic membrane are formed on a circumference of a specific virtual circle, the center of which is the specific point on the elastic membrane.
According to this method of discharging powder material, a virtual circle is drawn around the specific point on the elastic membrane and plural penetrating apertures are formed on its circumference. When each one of the plural penetrating apertures has the same size and shape, it shows the same behavior (the same deformation (expansion and contraction)) in case that a pulsating vibration air is supplied to vibrate the elastic membrane with its periphery being a vibration node.
As a result, if the positive pulsating vibration air supplied into the elastic membrane is constant and the penetrating apertures with the same size and shape are formed on the elastic membrane, the discharge amount of powder material from the quantitative discharge apparatus can be increased in a positive correlation to the number of the penetrating apertures on the elastic membrane.
According to the method of discharging powder material of the present invention, the plural penetrating apertures of the elastic membrane are formed at even intervals on the circumference of a specific virtual circle.
In this quantitative discharge apparatus, a virtual circle is drawn around a specific point on the elastic membrane and plural penetrating apertures are formed on the virtual circle at even intervals. If each one of plural penetrating apertures has the same size and shape, the elastic membrane can execute vibration with high reproducibility with its center being a vibration antinode and its periphery being a vibration node when the positive pulsating vibration air is supplied on the elastic membrane.
According to this discharge method for powder material, comparing with the discharge method using the elastic membrane on which plural penetrating apertures are partialized on an area, the discharge amount of powder material is quantitatively changed keeping a positive relation to the number of the penetrating apertures on the elastic membrane.
Namely, according to this discharge method for powder material, the number of penetrating apertures are increased in such a manner that a virtual circle is drawn around a specific point on the elastic membrane and plural numbers of the apertures are formed at even intervals on the virtual circle, thereby the discharge amount of powder material is quantitatively changed keeping a positive relation to the number of the penetrating apertures on the elastic membrane.
According to the method of discharging powder material of the present invention, each one of the plural penetrating apertures of the elastic membrane is formed as a cut aperture.
In the method of discharging powder material, because the plural penetrating apertures on the elastic membrane are formed cut aperture (slit), as long as the positive pulsating vibration air supplied into the elastic membrane is constant, the discharge amount of powder material from the apertures (slit) formed on the membrane is designed to be constant, thereby quantitative discharge of powder material can be achieved.
According to the method of discharging powder material of the present invention, a cutting direction of the cut aperture on the elastic membrane is a tangential direction of the circumference of a specific virtual circle.
In this quantitative discharge apparatus, the cutting direction of the cut apertures (slit) is a tangential direction of the circumference of the circle on which plural apertures are formed and the elastic membrane repeats the cycle at high reproducibility wherein each plural aperture is opened like a letter V, then is closed, and again is opened like a reverse V-shape while being vibrated by the positive pulsating vibration air supplied thereto.
As a result, applying this discharge method for powder material, a large amount of powder material on the elastic membrane can be quantitatively discharged through the cut apertures (slit) comparing with the discharge method wherein the elastic membrane is formed with plural cut apertures (slit) which are the same shape, size and number and of which cutting direction is in radial from a virtual circle to its periphery and wherein the positive pulsating vibration air having the same conditions as the present invention is used.
According to the method of discharging powder material of the present invention, a penetrating aperture is further provided on a specific point on the elastic membrane.
In this method, the discharge amount of powder material is increased keeping a positive relation at a ratio of providing a further penetrating aperture at the center of the virtual circle on the elastic membrane.
According to the method of discharging powder material of the present invention, the discharge amount of powder material is adjustable at a desired value depending on the number of the plural penetrating apertures formed on the elastic membrane. A predetermined number of penetrating apertures are at first formed on a tangent of the circumference of a specific virtual circle on the elastic membrane, the tangent including the contact point with the circumference. A predetermined number of penetrating apertures are next formed on a line with a specific angle across the tangent of the circumference of a specific virtual circle on the elastic membrane, the line including the contact point with the circumference.
In this discharge method, for controlling the discharge amount of powder material from the quantitative discharge apparatus, when the discharge amount of powder material from the apparatus is remarkably small comparing with the objective amount, the discharge amount of powder material from the apparatus is subject to be approached to the objective discharge amount with a small number of penetrating apertures (cut aperture (slit)) by providing the apertures on the tangent of a virtual circle drawn around a specific point. Thereafter, penetrating apertures (cut aperture (slit)) are further formed on the virtual circle drawn around a specific point so as to have an angle against the tangent of the circle so that the discharge amount of powder material is controlled to be an objective amount. As a result, the amount of powder material discharged from the quantitative discharge apparatus can be accurately controlled to be an objective amount.
According to the method of discharging powder material of the present invention, a predetermined number of penetrating apertures on the elastic membrane are formed on the circumference of the virtual circle around the specific point on the elastic membrane in a radial direction from the specific point of the virtual circle.
In this discharge method, for controlling the discharge amount of powder material from the quantitative discharge apparatus, when the discharge amount of powder material from the apparatus is remarkably small comparing with the objective amount, the discharge amount of powder material from the apparatus is subject to be approached to the objective discharge amount with a small number of penetrating apertures (cut aperture (slit)) by providing the apertures on the tangent of the virtual circle drawn around a specific point. Thereafter, penetrating apertures (cut aperture (slit)) are further formed on the circumference of the virtual circle drawn around a specific point so as to have an angle against the tangent of the circle so that the discharge amount of powder material is controlled to be an objective amount. Further, cut apertures (slit) are formed on the circumference of the virtual circle in radial from the specific point of the virtual circle on the elastic membrane, thereby the discharge amount of powder material is minutely controlled to the objective amount. As a result, the amount of powder material discharged from the quantitative discharge apparatus can be more accurately controlled to be an objective amount.
According to the method of discharging powder material of the present invention, the specific point on the elastic membrane accords with the center of the outline shape of the elastic membrane.
In this discharge method, the center of the virtual circle drawn on the elastic membrane agrees with the center of the of the elastic membrane which is the center of the antinode of vibration when the membrane is vibrated by the positive pulsating vibration air and plural penetrating apertures are formed on thus drawn virtual circle, thereby the apertures represent substantially the same behavior.
As the result, applying this discharge method for powder material, when the positive pulsating vibration air supplied to the elastic membrane is constant, the discharge amount of powder material can be quantitatively varied while the discharge amount keeps an almost positive relation to the number of the penetrating apertures formed on the membrane.
According to the method of discharging powder material in the present invention, the specific point on the elastic membrane accords with the center of gravity of the elastic membrane.
In this discharge method, the center of the virtual circle drawn on the elastic membrane agrees with the center of gravity of the elastic membrane which is the center of the antinode of vibration when the membrane is vibrated by the positive pulsating vibration air and plural penetrating apertures are formed on thus drawn virtual circle, thereby the apertures represent substantially the same behavior.
As the result, according to this method of discharging powder material, when the positive pulsating vibration air supplied to the elastic membrane is constant, the discharge amount of powder material can be quantitatively varied while the discharge amount keeps an almost positive relation to the number of the penetrating apertures formed on the membrane.
According to the method of discharging powder material of the present invention, the specific point on the elastic membrane accords with the center of the node of vibration which appears on the elastic membrane when the positive pulsating vibration air is supplied into the elastic membrane.
In this discharge method, the virtual circle is drawn around the center of antinode of vibration on the elastic membrane, the antinode being made by the positive pulsating vibration air supplied on the elastic membrane, and plural penetrating apertures are formed on thus drawn virtual circle, thereby the apertures represent substantially the same behavior.
As the result, applying this discharge method, when the positive pulsating vibration air supplied to the elastic membrane is constant, the discharge amount can be quantitatively varied while the discharge amount keeps an almost positive relation to the number of the penetrating apertures formed on the membrane.
According to the method of discharging powder material of the present invention, the positive pulsating vibration air is supplied from below the elastic membrane.
This discharge method applies the construction such that a positive pulsating vibration air is supplied under the elastic membrane so that a powder material spray apparatus with high quantitativeness which accurately sprays powder material with a desirable concentration at a desired place can be easily composed by utilizing a positive pulsating vibration air supplied for vibrating the elastic membrane as a pneumatic transport means of the powder material discharged from the plural penetrating apertures of the elastic membrane.
According to the method of discharging powder material of the present invention, the positive pulsating vibration air is supplied from above the powder material stored in the tubular body.
This discharge apparatus is constructed such that the positive pulsating vibration air is supplied from above the powder material stored in the tubular body so that caking of powder material doesn""t occur on the cone like a conventional hopper.
As a result, such a discharge method is superior in quantitativeness of discharge material from the plural penetrating apertures.
According to the method of discharging powder material of the present invention, the elastic membrane is attached to the lower portion of the tubular body with by means of an elastic membrane installation means. The elastic membrane installation means comprises a pedestal with an opening at its center, a push-up member with an opening at its center, which is disposed in the standing status on the pedestal and a presser member with an opening at its center, the opening being a little larger than the periphery size of the push-up member. The pedestal has on its surface an annular V-groove so formed as to surround the opening of the pedestal outside of the periphery of the push-up member and outside of the opening of the pedestal, whereas the presser member has on its surface facing the pedestal an annular V-shape projection portion so formed as to engage into the annular V-groove on the surface of the pedestal. The push-up member is disposed on the surface of the pedestal, on which the elastic membrane is disposed, and further the presser member is so tightly secured as to cover the push-up member together with the elastic membrane to the pedestal, whereby the elastic membrane is expanded from its inner side to its outer side by being pushed up toward the presser member by means of the push-up member, while the periphery part of the elastic membrane is held between the periphery part of the push-up member and the surface forming an opening of the presser member and further expanded to be held between the annular V-groove formed on the surface of the pedestal and the annular V-shape projection portion formed on the surface facing the pedestal, and wherein the presser member is secured to the lower portion of the tubular body.
In this discharge method, the elastic membrane with plural penetrating apertures is attached to the lower part of the tubular body by means of the elastic membrane installation means. The elastic membrane is placed on the push-up member placed on the pedestal and the presser member is tightened to the pedestal, thereby the membrane is pushed into the presser member by the push-up member. As a result, the elastic membrane is expanded from its inner side to its outer side by being pushed into the direction of the presser member.
At first, the elastic membrane expanded by the push-up member is gradually inserted between the V-groove formed on the pedestal and the V-shaped projection formed on the surface of the presser member facing the pedestal via the space between the periphery of the push-up member and the surface (inner surface) forming opening of the presser member.
Furthermore, as the presser member is fastened to the pedestal, the elastic membrane comes to be held between the periphery of the push-up member and the inner surface of opening of the presser member while being pushed up into the presser member by the push-up member. When the elastic membrane is further pushed up into the presser member by the push-up member, the expanded part of the elastic membrane from inside to outside is held between the V-groove of the pedestal and the V-shaped projection on the surface of the presser member facing the pedestal.
As mentioned above, according to this discharge method, the elastic membrane can be uniformly stretched by a simple operation such that the elastic membrane is placed on the push-up member on the pedestal and the presser member is tightened to the pedestal.
According to the method of discharging powder material of the present invention, an inclined plane is formed on the periphery of the push-up member, the inclined plane having a bottom part broader than its top part when seen in section.
The elastic membrane installation means used for this discharge method has the inclined plane which is enlarged from top to bottom at the periphery of the push-up member of the elastic membrane installation means of the quantitative discharge apparatus. Therefore, the expanded part of the elastic membrane from inside to outside by being pushed up into the presser member is easily moved between the V-groove annularly formed on the pedestal and the V-shaped projection annularly formed on the surface of the presser member facing the pedestal.
When the presser member is fastened to the pedestal, the distance between the inclined plane of the periphery of the push-up member and the inner circumference of opening of the presser member becomes small, and the elastic membrane is tightly held between the inclined plane of the push-up member and the inner circumference of opening of the presser member, preventing the elastic membrane from being slack.
Thus, applying this method for discharging powder material, the elastic membrane doesn""t get slack during usage so that the quantitative discharge apparatus can keep its accurate operation for a long time.
This discharge method applies the construction such that the inclined plane is formed on the periphery of the push-up member when seen sectionally. For attaching the elastic membrane on the elastic membrane installation means, the elastic membrane can be kept evenly and uniformly expanded by a simple operation such that the elastic membrane is placed on the push-up member on the pedestal and the presser member is tightened to the pedestal. Further, the elastic membrane doesn""t get slack during operation according to this method, thereby the quantitative discharge apparatus capable of keeping accurate operation for a long timecan be achieved.